KR20220167888A - A method for preparing a nanocellulose using nonionic surfactants - Google Patents

Abstract

The present invention relates to a physical interaction technology of nanocellulose, and more particularly, to a method for separating water in an aqueous solution through a physical interaction promoter of nanocellulose, and to the synthesis of the interaction promoter of nanocellulose, capable of increasing the dispersibility of the nanocellulose in a polymer matrix and improving the physical properties of a polymer composite material.

Description

Method for preparing a nanocellulose using nonionic surfactants {A method for preparing a nanocellulose using nonionic surfactants}

The present invention relates to a physical interaction technology of nanocellulose, and more particularly, to a method for separating nanocellulose from water in an aqueous solution through a physical interaction accelerator, and to increase the dispersibility of nanocellulose in a polymer matrix and to develop a polymer composite material. It relates to the synthesis of cellulose interaction promoters capable of improving physical properties.

Cellulose, the most abundant polymer material on earth, has recently succeeded in economically manufacturing certain nano-sized fibers from wood using various methods, and is a new reinforcing agent that can replace carbon fibers or glass fibers used as reinforcing agents for general polymer composite materials. Be in the spotlight.

As a representative example, nanocellulose (NC) in the form of fibers has a large surface area and high aspect ratio, so it not only has excellent mechanical properties, but also has eco-friendliness, biodegradability, and biocompatibility. There are advantages.

Currently, automobile-related companies around the world are constantly striving to reduce the weight of automobiles. Polyurethane, which is used as a representative industrial material for automobiles, is mainly made of petroleum-derived polyol and isocyanate such as toluene diisocyanate (TDI) or methylene diphenyl diisocyanate (MDI). However, the use of existing petroleum polymer materials will be limited due to the introduction of a carbon tax by the Kyoto Protocol in 2013. Automakers have established a strategy to use sustainable plastic for various polymer materials used in automobile manufacturing. The global automotive industry is actively responding to ever-strengthening environmental regulations. Recently, green carbon-based polyol using vegetable oil as a raw material has been manufactured mainly in Germany, and Ford Motor Company has produced 5% of Mustang car seats with soy bean oil-based foam using soybean oil-based bio-polyol with high NOP content. . In the case of one small passenger car, 150 kg of plastic is usually used, and polyurethane uses about 15 to 20% of the total plastic. The amount of polyurethane used in automobiles averages 22.5 to 30 kg. According to Utech data, using biopolyol instead of petroleum-derived polyurethane is expected to save 272.2 tons of carbon dioxide per year. When the content of biopolyol-derived polyurethane increases, physical properties of polyurethane decrease compared to pure polyurethane. To compensate for this, microcrystalline cellulose was combined with or filled with polyurethane.

However, due to the hydroxyl group (-OH) on the surface of cellulose, it has strong hydrophilic properties, and it is difficult to separate from water in an aqueous solution state, and when mixed with a hydrophobic polymer matrix, it is not evenly dispersed and aggregates or rapidly precipitates.

In order to solve this problem, the conventional method of modifying the surface of nano cellulose is to impart hydrophobicity through a method of chemically modifying the hydroxyl group on the surface or a method of modifying by electrostatic attraction using a cationic surfactant.

The above chemical modification method typically uses a method of modifying a hydroxyl group using isocyanate as a functional group and using a urethane bond. In this case, high energy such as application of high heat or freezing is required in the process of completely removing water from the water-dispersed nanocellulose, and considering all organic solvents, catalysts, and reactants for chemical reforming, the synthesis process is It is not suitable for bulk cellulose surface modification due to complexity and economic problems. Chemical modification methods announced for imparting hydrophobicity, including a method using alkenylsuccinic anhydride known as another representative method, are also not suitable for surface modification of large amounts of nanocellulose due to the aforementioned problems. Accordingly, surface modification using the electrostatic attraction of cationic surfactants such as cetyltrimethylammonium bromide (CTAB) and dimethyldioctadecylammonium chloride (DODMAC) has been announced, but several problems caused by cations used as surface modifiers in subsequent synthesis processes have been reported. There are difficulties in solving the problem of side reactions.

As interest in the environment gradually increases worldwide, efforts are being made to synthesize petroleum-based polymers into environmentally friendly, renewable and sustainable materials. In accordance with the interest of the global market, the inventors of the present invention obtained raw materials from plants to produce nanocellulose, which has properties such as improved mechanical strength and lightness of composite materials along with environmentally friendly properties, as a reinforcing material for polymer composite materials. Production and process system Various efforts for development have led to the completion of the present invention.

Korean Patent Publication No. 10-2018-0128251

Accordingly, one aspect of the present invention is to provide a novel nanocellulose modified with a surface modifier based on a nonionic surfactant and a manufacturing method thereof in order to fundamentally solve the above problems.

One aspect of the present invention is to provide a novel nonionic surfactant for modifying nanocellulose and a method for preparing the same.

Another aspect of the present invention is to provide a method for preparing nanocellulose modified with a novel surface modifier and nanocellulose prepared by the method.

Another aspect of the present invention is to provide a polymer matrix with improved dispersibility of nano-cellulose and a method for preparing the same.

Specifically, an object of the present invention is to enable the separation of water and nanocellulose in an aqueous solution through a physical interaction accelerator of cellulose, and then to increase the dispersibility of cellulose in a polymer matrix and at the same time to improve the physical properties of a polymer composite material. It is to provide a method for preparing an interaction promoter capable of precipitating and dispersing a large amount of cellulose and a method for precipitating and dispersing cellulose.

In order to solve the above problems, the following solutions of the present invention are provided.

One aspect of the present invention provides a nanocellulose surface modifier, wherein the nanocellulose surface modifier is a nonionic surfactant in which a hydrophilic group is ring-opened with glycidol.

In one aspect of the present invention, the nonionic surfactant is a carboxylic acid compound having 4 to 25 carbon atoms, an alcohol compound having 4 to 25 carbon atoms, and an amine compound having 4 to 25 carbon atoms, by a ring-opening reaction between any one or more of glycidol Provided is a nonionic surfactant prepared, a nanocellulose surface modifier.

In one embodiment, the carboxylic acid compound having 4 to 25 carbon atoms is butyric acid, valeric acid, caproic acid, enatic acid, caprylic acid, ferragonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, Myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadesilic acid, arachitic acid, henicosilic acid, behenic acid, trichosilic acid, lignoceric acid, alpha-linolenic acid, stearidonic acid , Eicosapentaenoic acid, docosahexaenoic acid, linolic acid, gamma-linoleic acid, dihomo-gamma-linolenic acid, arachinonic acid, docosatetraenoic acid, palmitoleic acid, vasenic acid , Paulinic acid, oleic acid, elaidic acid, gondoic acid, erusic acid, nerbonic acid, and at least one selected from mead acid, and the alcohol compound having 4 to 25 carbon atoms is butanol, pentanol, hexanol, heptanol, and octanol. , nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, palmityl alcohol, octadecanol, nonadecanol, icosanol, heneicosanol, docosanol, tri At least one selected from cosanol, tetracosanol, and pentacosanol, and the amine compound having 4 to 25 carbon atoms is butanamine, pentanamine, hexanamine, heptanamine, octanamine, nonanamine, decaneamine, and undecane. Amine, dodecaneamine, tritecanamine, tetradecaneamine, pentadecaneamine, hexadecaneamine, heptadecanamine, octadecanamine, nonadecanamine, icosaneamine, hennicosanamine, docosanamine, trichosanamine , It provides a nanocellulose surface modifier, which is at least one selected from tetracosanamine and pentacosanamine.

In one aspect of the present invention, the nanocellulose surface modifier provides a hyperbranched polyglycidol (HBPG) form, a nanocellulose surface modifier.

In one aspect of the present invention, the nanocellulose surface modifier is any one or more of a carboxylic acid compound having 4 to 25 carbon atoms, an alcohol compound having 4 to 25 carbon atoms, and an amine compound having 4 to 25 carbon atoms and glycidol in a ratio of 1: 1 to 30 It provides a nanocellulose surface modifier prepared by reacting in a molar ratio of.

In one aspect of the present invention, the nanocellulose surface modifier is prepared by reacting a carboxylic acid compound having 4 to 25 carbon atoms with glycidol in a molar ratio of 1: 1 to 8, to provide a nanocellulose surface modifier.

In one aspect of the present invention, the nanocellulose surface modifier provides a nanocellulose surface modifier having 1 to 10 hydroxyl groups.

In the method for producing a nanocellulose surface modifier of any one of the aspects of the present invention, the method comprises any one or more of a carboxylic acid compound having 4 to 25 carbon atoms, an alcohol compound having 4 to 25 carbon atoms, and an amine compound having 4 to 25 carbon atoms Injecting a catalyst; Nitrogen purging at 80° C. to 120° C. for 30 minutes to 5 hours; and reacting for 4 to 48 hours after adding glycidol.

Another aspect of the present invention is a method for producing surface-modified nanocellulose, the method comprising: mixing a nanocellulose aqueous solution and the nanocellulose surface modifier of any one of the aspects of the present invention; Centrifuging the mixed solution; and removing a large amount of water after centrifugation.

In another aspect of the present invention, the nanocellulose and the nanocellulose surface modifier contained in the nanocellulose aqueous solution are mixed in a weight ratio of 0.2 to 3 to 1, to provide a method for producing nanocellulose with a modified surface.

In another aspect of the present invention, a surface-modified nanocellulose prepared according to another aspect of the present invention is provided.

In one embodiment, the surface-modified nanocellulose provides surface-modified nanocellulose in the form of a slurry.

In one embodiment, the surface-modified nanocellulose provides surface-modified nanocellulose, wherein the surface-modifying agent and the nanocellulose are bonded through a hydrogen bond.

Another aspect of the present invention is a method for manufacturing a polyol polymer matrix in which nanocellulose is dispersed, wherein nanocellulose whose surface is modified with the nanocellulose surface modifier of any one of the aspects of the present invention is dispersed, injected, or added to a polyol. It provides a method for producing a polyol polymer matrix in which nanocellulose is dispersed, including;

In another aspect of the present invention, the method provides a method for producing a polyol polymer mattress in which nanocellulose is dispersed, further comprising removing water from the mixed solution.

In another aspect of the present invention, a method for producing a polyol polymer mattress in which nanocellulose is dispersed, wherein the surface-modified nanocellulose is included in 0.1% to 10% by weight of polyol based on the total weight of the polyol polymer mattress to provide.

Another aspect of the present invention provides a polyol polymer matrix in which nanocellulose is dispersed.

In one embodiment, the polyol polymer mattress provides a polyol polymer mattress with improved tensile strength and heat resistance.

When preparing nanocellulose as a surface modifier according to one aspect of the present invention, precipitation is facilitated in an aqueous solution of nanocellulose due to a physical hydrogen bond between the surface modifier and nanocellulose.

In the case of preparing nanocellulose as a surface modifier according to one aspect of the present invention, the dispersibility in the polymer matrix can be increased due to the hydrophobic nature of the alkyl chain of the surface modifier physically bonded to the nanocellulose.

In the case of preparing nanocellulose and a polymer matrix including the same as the surface modifier according to one aspect of the present invention, the number of hydroxyl groups of the surface modifier may be adjusted to increase dispersibility and improve physical properties depending on the type of polymer matrix.

In the case of preparing nanocellulose with the surface modifier according to one aspect of the present invention, since the surface of nanocellulose is modified only by physical interaction, side reactions that may occur in subsequent processes can be minimized.

In the case of producing nanocellulose as a surface modifier according to one aspect of the present invention, there is an advantage in that inexpensive starting materials are used and the surface modification process can be performed at a relatively low temperature without chemical reaction. Due to this, it is possible to proceed with a surface modification process for a large amount of nanocellulose.

When preparing nanocellulose as a surface modifier according to one aspect of the present invention, since various nonionic surfactants having hydroxyl groups, carboxyl groups, and amine groups sold on the market are used as starting materials, nanocellulose dispersion can be appropriately used in various polymers. there is.

In the case of preparing nanocellulose and a polymer matrix including the same as the surface modifier according to one aspect of the present invention, an excellent heat resistance improving effect is exhibited.

When preparing nanocellulose and a polymer matrix including the same as the surface modifier according to one aspect of the present invention, it exhibits an excellent tensile strength improving effect.

1 is a schematic diagram of surface modification of cellulose according to the present invention. Nanocellulose exists in the form of water dispersion during the manufacturing process (cannot be dissolved to the nano diameter by dry method), and in order to separate the nanocellulose that exists in the form of water dispersion from water, an interaction promoter (surface modifier) is prepared , will be put in. Then, it is precipitated by physical hydrogen bonding of nanocellulose and surface modifier, and the surface of nanocellulose + interaction promoter has hydrophobicity due to the alkyl group of interaction promoter. When the material obtained in this way is dispersed in a polymer or the like, an effect of improving the degree of dispersion with appropriate mutual polarity is obtained.
Figure 2 is a photograph of separating nanocellulose and water.
3 is a result of Experimental Example 1.
4 is a result of Experimental Example 2-1.
5 is a result of Experimental Example 2-2.
6 is a result of Experimental Example 3.
7 is a result of Experimental Example 4.
8 is a result of Experimental Example 5.
9 is a result of Experimental Example 6.
10 is the result of Experimental Example 7.
11a and 11b are results of Experimental Example 8.
12 is a result of Experimental Example 9.

If it is determined that the gist of the present invention may be obscured, descriptions of known configurations and functions will be omitted. "Including" in this specification means that it may further include other components unless otherwise specified.

In this specification, where ranges are stated for a variable, it will be understood that the variable includes all values within the stated range inclusive of the stated endpoints of the range. For example, a range of "5 to 10" includes values of 5, 6, 7, 8, 9, and 10, as well as any subrange of 6 to 10, 7 to 10, 6 to 9, 7 to 9, and the like. inclusive, as well as any value between integers that fall within the scope of the stated range, such as 5.5, 6.5, 7.5, 5.5 to 8.5 and 6.5 to 9, and the like. Also, for example, the range of "10% to 30%" includes values such as 10%, 11%, 12%, 13%, etc., and all integers up to and including 30%, as well as values from 10% to 15%, 12% to 12%, etc. It will be understood to include any sub-range, such as 18%, 20% to 30%, and the like, as well as any value between reasonable integers within the scope of the stated range, such as 10.5%, 15.5%, 25.5%, and the like.

Hereinafter, the present invention will be described in detail.

'Surface modification' of the present invention means changing functional groups or functional groups present on the surface of nanocellulose. Preferably, a hydrophilic functional group or functional group may be changed to a non-hydrophilic or hydrophobic functional group or functional group, or an amine functional group or functional group may be added, but is not limited thereto. In addition, preferably, the surface may be modified using a nonionic surfactant ring-opened with glycidol described in the present invention, but is not limited thereto.

A method for preparing a physical interaction promoter of cellulose using a surfactant according to the present invention comprises the steps of preparing an interaction promoter; Mixing the interaction promoter with the nano-cellulose dispersion and separating it from water; and dispersing the surface-modified nanocellulose in a polymer matrix after centrifuging the stirred liquid mixture.

The present invention provides the following nanocellulose surface modifier, a method for precipitating (separating or preparing) nanocellulose using the same, and a method for dispersing the surface-modified nanocellulose in a polymer.

[Method for manufacturing interaction promoter] (HBPG: Hyperbranched polyglycidol, a substance in which glycidol is bound to a functional group having an alkyl chain)

로 질소 퍼징 후 글리시돌을 적가하는 단계; 및 (c) 24시간 반응 후 상호작용 촉진제를 제조하는 단계를 제공하여 상호작용 촉진제인 나노셀룰로오스 표면개질제의 제조 방법을 제공한다.In one embodiment, the present invention provides a method comprising the steps of: (a) selecting, as a starting material, one kind of organic material capable of substituting a functional group with a hydroxyl group through a ring-opening reaction of glycidol on a functional group having an alkyl chain, and introducing a catalyst; (b) 100 for 1 hour

adding glycidol dropwise after purging with nitrogen; And (c) providing a step of preparing an interaction promoter after 24 hours of reaction to provide a method for preparing a nanocellulose surface modifier, which is an interaction promoter.

[Method of Precipitating Nanocellulose Using Interaction Promoters]

In one embodiment, the present invention comprises (a) mixing a nano-cellulose aqueous solution and an interaction promoter (see FIG. 1); (b) centrifuging the mixed solution (see FIGS. 2 and 3); (c) by removing a large amount of water after centrifugation to provide a method for precipitating nanocellulose by providing a step of preparing surface-modified nanocellulose in a slurry state including a small amount of water.

[Method of Dispersing Nano Cellulose in Polymer]

In one embodiment, the present invention comprises (a) mixing nano-cellulose and polyol in slurry form; and (b) preparing a polyol in which cellulose is dispersed by completely removing water (FIG. 8).

Therefore, an object of the present invention is to enable the separation of water and nanocellulose in an aqueous solution through a surface modifier having a physical interaction promoting effect on existing nanocellulose. In addition, an object of the present invention is to provide a method for improving the physical properties of a polymer composite material while increasing the dispersibility of the separated nanocellulose in a polymer matrix. In addition, an object of the present invention is to provide a method for preparing a nanocellulose surface modifier (interaction promoter) capable of precipitating and dispersing a large amount of cellulose and a method for precipitating and dispersing cellulose.

According to the present invention, by adding a nonionic surfactant to the nano-cellulose aqueous solution, a physical hydrogen bond is formed with a functional group on the surface of cellulose, and an alkyl chain representing the hydrophobicity of cellulose is introduced (FIG. 1). Due to this, it is possible to increase the dispersibility in the polymer matrix by increasing the precipitation in aqueous solution and the hydrophobicity of cellulose. In addition, by adjusting the number of hydroxyl groups of the surfactant to suit the characteristics of the polymer matrix, the ratio of hydrophilicity and hydrophobicity can be adjusted, and the dispersibility in the polymer matrix can be increased and the physical properties of the polymer composite material can be improved. (FIG. 9, FIG. 10, FIG. 11, FIG. 12, FIG. 13)

The physical interaction according to the present invention is a method of modifying the surface of nanocellulose using only intermolecular physical bonds, and side reactions that may occur in subsequent processes can be minimized.

In addition, the process according to the present invention is a surface modifier synthesized using an inexpensive starting material, and has an advantage in that the surface modification process can be performed at a relatively low temperature without chemical reaction. Due to this, it is possible to proceed with a surface modification process for a large amount of nano cellulose.

The hydroxyl group of various commercially available nonionic surfactants having hydroxyl, carboxyl, and amine functional groups was changed only by ring-opening polymerization of glycidol, and the degree of hydrophilicity and hydrophobicity of nonionic surfactants can be changed. Due to this, it is possible to appropriately use the cellulose dispersion in various polymers.

Hereinafter, various aspects of the present invention will be described.

One aspect of the present invention provides a nanocellulose surface modifier, wherein the nanocellulose surface modifier is a nonionic surfactant in which a hydrophilic group is ring-opened with glycidol.

In one aspect of the present invention, the nonionic surfactant is a carboxylic acid compound having 4 to 25 carbon atoms, an alcohol compound having 4 to 25 carbon atoms, and an amine compound having 4 to 25 carbon atoms, by a ring-opening reaction between any one or more of glycidol Provided is a nonionic surfactant prepared, a nanocellulose surface modifier.

In one embodiment, the carboxylic acid compound having 4 to 25 carbon atoms is butyric acid, valeric acid, caproic acid, enatic acid, caprylic acid, ferragonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, Myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadesilic acid, arachitic acid, henicosilic acid, behenic acid, trichosilic acid, lignoceric acid, alpha-linolenic acid, stearidonic acid , Eicosapentaenoic acid, docosahexaenoic acid, linolic acid, gamma-linoleic acid, dihomo-gamma-linolenic acid, arachinonic acid, docosatetraenoic acid, palmitoleic acid, vasenic acid , Paulinic acid, oleic acid, elaidic acid, gondoic acid, erusic acid, nerbonic acid, and at least one selected from mead acid, and the alcohol compound having 4 to 25 carbon atoms is butanol, pentanol, hexanol, heptanol, and octanol. , nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, palmityl alcohol, octadecanol, nonadecanol, icosanol, heneicosanol, docosanol, tri At least one selected from cosanol, tetracosanol, and pentacosanol, and the amine compound having 4 to 25 carbon atoms is butanamine, pentanamine, hexanamine, heptanamine, octanamine, nonanamine, decaneamine, and undecane. Amine, dodecaneamine, tritecanamine, tetradecaneamine, pentadecaneamine, hexadecaneamine, heptadecanamine, octadecanamine, nonadecanamine, icosaneamine, hennicosanamine, docosanamine, trichosanamine , It provides a nanocellulose surface modifier, which is at least one selected from tetracosanamine and pentacosanamine.

In one aspect of the present invention, the nanocellulose surface modifier provides a hyperbranched polyglycidol (HBPG) form, a nanocellulose surface modifier.

In one aspect of the present invention, the nanocellulose surface modifier is any one or more of a carboxylic acid compound having 4 to 25 carbon atoms, an alcohol compound having 4 to 25 carbon atoms, and an amine compound having 4 to 25 carbon atoms and glycidol in a ratio of 1: 1 to 30 It provides a nanocellulose surface modifier prepared by reacting in a molar ratio of.

In one aspect of the present invention, the nanocellulose surface modifier is prepared by reacting a carboxylic acid compound having 4 to 25 carbon atoms with glycidol in a molar ratio of 1: 1 to 8, to provide a nanocellulose surface modifier.

In one aspect of the present invention, the nanocellulose surface modifier provides a nanocellulose surface modifier having 1 to 10 hydroxyl groups.

In the method for producing a nanocellulose surface modifier of any one of the aspects of the present invention, the method comprises any one or more of a carboxylic acid compound having 4 to 25 carbon atoms, an alcohol compound having 4 to 25 carbon atoms, and an amine compound having 4 to 25 carbon atoms Injecting a catalyst; Nitrogen purging at 80° C. to 120° C. for 30 minutes to 5 hours; and reacting for 4 to 48 hours after adding glycidol.

Another aspect of the present invention is a method for producing surface-modified nanocellulose, the method comprising: mixing a nanocellulose aqueous solution and the nanocellulose surface modifier of any one of the aspects of the present invention; Centrifuging the mixed solution; and removing a large amount of water after centrifugation.

In another aspect of the present invention, the nanocellulose and the nanocellulose surface modifier contained in the nanocellulose aqueous solution are mixed in a weight ratio of 0.2 to 3 to 1, to provide a method for producing nanocellulose with a modified surface.

In another aspect of the present invention, a surface-modified nanocellulose prepared according to another aspect of the present invention is provided.

In one embodiment, the surface-modified nanocellulose provides surface-modified nanocellulose in the form of a slurry.

In one embodiment, the surface-modified nanocellulose provides surface-modified nanocellulose, wherein the surface-modifying agent and nanocellulose are bonded through a hydrogen bond.

Another aspect of the present invention is a method for manufacturing a polyol polymer matrix in which nanocellulose is dispersed, wherein nanocellulose whose surface is modified with the nanocellulose surface modifier of any one of the aspects of the present invention is dispersed, injected, or added to a polyol. It provides a method for producing a polyol polymer matrix in which nanocellulose is dispersed, including;

In another aspect of the present invention, the method provides a method for producing a polyol polymer mattress in which nanocellulose is dispersed, further comprising removing water from the mixed solution.

In another aspect of the present invention, a method for producing a polyol polymer mattress in which nanocellulose is dispersed, wherein the surface-modified nanocellulose is included in 0.1% to 10% by weight of polyol based on the total weight of the polyol polymer mattress to provide.

Another aspect of the present invention provides a polyol polymer matrix in which nanocellulose is dispersed.

In one embodiment, the polyol polymer mattress provides a polyol polymer mattress with improved tensile strength and heat resistance.

In one embodiment, the polyol polymer mattress is polyurethane.

Hereinafter, the present invention will be described in more detail through the following preparation examples, examples and experimental examples. However, these preparation examples, examples, and experimental examples are for exemplifying the present invention, and the scope of the present invention is not limited thereto.

Preparation Example 1: Preparation of nanocellulose surface modifier

Example 1: Using an initiator terminally terminated with a hydroxyl group (span 80)

( Span80 : Glycidol = 1 : 3 mol ratio )

(One) manufacturing method

① Prepare Sorbitan Monooleate, Span80 (initiator), Glycidol (monomer), and DMC (catalyst).

② Put 20 g of Span 80 and 0.03 g of DMC catalyst (0.3 wt% of Glycidol) into a 250ml round flask.

③ Circulate nitrogen and remove moisture with stirring at 90 ° C for an hour.

④ Add 10.37 g of Glycidol at a rate of 1 ml/h using a syringe pump to a round flask that has been purged with nitrogen for one hour.

⑤ After the injection of glycidol, the reaction proceeds for an additional 2 hours, and the completion of the reaction is determined through ¹ H NMR.

⑥ Add chloroform to the round flask after the reaction and dissolve the product.

⑦ At this time, polyglycidol and DMC catalyst, which are by-products floating in chloroform without being dissolved, are filtered through a filter paper.

⑧ After blowing off all the chloroform solvent, put it in a vacuum oven and dry it sufficiently.

(2) Manufacturing result

Upon ¹ H NMR confirmation, the desired product was confirmed by the disappearance of the peak corresponding to glycidol and the increase of the corresponding peak (3.4 to 4.6 ppm) of the hydrophilic group.

Example 2: Use of an initiator terminated with a carboxyl group (stearic acid)

(One) manufacturing method

- Step 1

① Prepare Stearic acid (initiator), Glycidol (monomer), and Triethylamine (catalyst).

② Add 76.81 g (0.27 mol) of stearic acid (S.A) to a 250ml round flask and melt at 70 ℃. (Tm : 69.3 ℃)

③ After S.A is completely dissolved, add 1.1 g of triethylamine, circulate nitrogen, and stir at 70 ° C for an hour to remove water (take out glycidol, which is stored in a refrigerator, at room temperature in advance, considering volume expansion).

④ Add 40 g (0.54 mol) of Glycidol at a rate of 2 ml/min using a syringe pump to a round flask that has been purged with nitrogen for one hour.

⑤ The reaction proceeds for a total of 6 hours.

⑥ Add chloroform to the round flask after the reaction and dissolve the product.

⑦ At this time, polyglycidol and DMC catalyst, which are by-products floating in chloroform without being dissolved, are filtered with a filter paper.

⑧ Put the chloroform solvent in a separatory funnel, forcefully mix it with distilled water, and then purify it through layer separation.

⑨ Obtain only the chloroform solvent part, blow away all the solvent, and dry it sufficiently by putting it in a vacuum oven.

- Step2

① Prepare Stearoyl glycerol (initiator), Glycidol (monomer), and DMC (catalyst).

② Put 50 g of stearoyl glycerol and 0.055 g of DMC catalyst (0.3 wt% of Glycidol) into a 250ml round flask.

③ Circulate nitrogen and remove moisture with stirring at 100 ° C for an hour.

④ Add 18.6053 ml of Glycidol at a rate of 1.0336 ml/h using a syringe pump to a round flask that has been purged with nitrogen for one hour.

⑤ After the injection of glycidol, the reaction proceeds for an additional 2 hours, and the completion of the reaction is determined through 1H NMR.

⑥ Add chloroform to the round flask after the reaction and dissolve the product.

⑦ At this time, polyglycidol and DMC catalyst, which are by-products floating in chloroform without being dissolved, are filtered with a filter paper.

⑧ After blowing off all the chloroform solvent, put it in a vacuum oven and dry it sufficiently.

(2) Manufacturing result

Upon ¹ H NMR confirmation, it was confirmed that the desired product was produced due to the disappearance of the peak corresponding to glycidol and an increase in the corresponding peak (3.4 to 4.6 ppm) of the hydrophilic group.

Preparation Example 2: Preparation of surface-modified nanocellulose using a surface modifier

(One) manufacturing method

① Add 50 wt% of the surface modifier (surfactant) to CNF 1 wt% suspension and apply heat to disperse it sufficiently (heat to 70 ° C with stirring and disperse.)

② Using a centrifuge (5 min / 7000 rpm), layer separation occurs, and water in the upper layer is removed to obtain only the CNF slurry.

③ After adding to polyol (PTMG, PPG), stir with a magnetic bar and heat at 90 ℃ to sufficiently disperse.

(2) Manufacturing result

- It was confirmed that layer separation had occurred using a centrifuge, and it was confirmed that there was water in the upper layer and CNF slurry in the lower layer.

- It was confirmed that it was stably dispersed for a longer time than the polyol dispersed without surface modifiers such as PTMG and PPG.

Preparation Example 3: Preparation of a polymer in which surface-modified nanocellulose is dispersed

(One) manufacturing method

- Manufacture of CNF/Polyurethane composites

① Sufficiently remove moisture from 10 g of PTMG1000 in which CNF is dispersed as a surface modifier. (Processing mechanical stirring in a vacuum state in a closed system and proceeding at 90 ℃ for 3 hours)

② Lower the temperature by 60 ℃, add 3.364 g of Hexamethylene diisocyanate (HDI) in a nitrogen atmosphere and react for 3 hours. (NCO/OH=2)

③ Raise the temperature to 100 ℃, add 0.9 g of 1,4-Butanediol (BDO) as a chain extender, add 5 ml of purified DMF and 0.05 ml of a dibutyltin dilaurate catalyst, and polymerize for 1 hour.

④ After polymerization, put the polymerized polyurethane in DMF to make it in liquid form, pour it into a mold such as a beaker or petri dish made of Teflon, and remove the DMF at 70 ℃.

(2) Manufacturing result

- After confirming the state of -NCO peak at 2270 cm ^-1 through FT-IR measurement at each step, the completeness of polymerization is identified by completely disappearing in the final form.

- Identify structural characteristics through FT-IR, Raman, and XRD.

- Identify mechanical properties through UTM.

- Identify thermal characteristics through DSC and TGA.

Experimental Example 1. Nuclear Magnetic Resonance Spectroscopy (NMR) data of upper and lower layers after nanocellulose centrifugation

(1) NMR measurement of the nanocellulose prepared in Preparation Example 2 was performed.

(2) The experimental results were as shown in FIG. 3 . NMR measurements were performed on the nanocellulose (NC), the interaction promoter (HBPG), the precipitated portion, and the upper portion, respectively, and it was confirmed that NC and HBPG were present in the precipitated portion, and only water remained in the upper portion.

Experimental Example 2-1. Nuclear Magnetic Resonance Spectroscopy (NMR) of hydroxyl groups of surface modifiers

(1) 0.01 g to 0.015 g of a sample of the surface modifier prepared in Preparation Example 1 was sampled, sufficiently dissolved in 0.6 ml of CDCl ₃ as an NMR solvent, and then sampled, and then ¹ H NMR was measured.

(2) The experimental results were as shown in FIG. 4 .

- NMR was measured to confirm that the hydrophilic group portion increased according to the molar ratio of the initiator and glycidol, and as the amount of glycidol increased based on the terminal methyl group (-CH ₃ ) of the initiator, the peak of the hydrophilic group (Polyether backbone + Hydroxyl group, 3.4 ~ 4.6 ppm) was confirmed to increase.

Experimental Example 2-2. Contact angle data of nanocellulose film according to hydroxyl group control of surface modifier

(1) In Experimental Example 2-1 and FIG. 4, the surface modifier whose hydroxyl group was adjusted was put into a nanocellulose aqueous solution, and the contact angle data measured by filming the obtained material after precipitation was measured.

(2) The purpose of the experiment is to identify the increase in hydrophobicity of the nanocellulose film due to the surface modifier.

(3) In the experimental method, the contact angle was measured to determine the hydrophobic nature of the nanocellulose film according to the surface modifier change depending on the initiator and glycidol molar ratio.

(4) The experimental results were as shown in FIG. 5 . 5 is a nano-cellulose film prepared after adding an interaction promoter with two hydroxyl groups attached to an alkyl group from the left, and an interaction promoter with 4, 7, and 11 attached. As it goes to the right, the number of glycidols (OH number) increases and becomes hydrophilic, and as it goes to the left, it becomes hydrophobic, resulting in NCs with various polarities.

- Since the cellulose film can absorb moisture over time, it was judged that the accuracy over time was poor, and as a result of measuring the same time period, there was definitely a change depending on whether or not the surface modifier was added, but there was a tendency depending on the change and amount of the hydrophilic group It was judged that there was no

Experimental Example 3. Contact angle data of nanocellulose film according to surface modifier content

(1) S.A 4 sample in Preparation Example 1 and FIG. 4 was used.

(2) S.A 4 samples were 1/8, 1/4, 1/2 by weight of nanocellulose. A material obtained by adding 1 or 2 times was used. It was made into a film and the contact angle was measured.

(3) In the experimental method, the contact angle was measured to determine the hydrophobic nature of the nanocellulose film according to the change in the amount of the surface modifier.

(4) The experimental results were as shown in FIG. 6 . As a result of the experiment, as the amount of the surface modifier increased, the hydrophobicity increased, and it was possible to secure nanocellulose having various polarities through each content control. Since the cellulose film can absorb moisture over time, it was judged that the accuracy over time was poor, and as a result of the measurement at the same time, there was definitely a change depending on whether or not the surface modifier was added, but there was a tendency depending on the change and amount of the hydrophilic group. was judged to be absent.

Experimental Example 4. TEM picture measurement of polyol in which surface-modified nanocellulose is dispersed

(1) PTMG in which cellulose was dispersed with a surface modifier (50 wt% relative to cellulose) added in the procedure of Preparation Example 2 and PTMG in which cellulose was dispersed without a surface modifier were used as a comparative example.

(2) In the experimental method, after dispersing cellulose with or without surface modifier added in PTMG1000, which is a polyol, 1 mg of PTMG dispersed in cellulose was sampled with 1 ml of ethanol and distilled water (2:1) and dispersed. It was put on a TEM grid and TEM was measured.

(3) The experimental results were as shown in FIG. 7 . The left side of FIG. 7 is an image without adding the nonionic surfactant, and it is confirmed that polyol and CNF exist separately, but the right side shows that polyol exists uniformly around CNF. When the NC without the surface modifier on the left is put into Polyol, it does not disperse and exists in the form of agglomerates. When the NC made by adding the surface modifier on the right is put into polyol, it exists in a dispersed form.

Experimental Example 5. Polyol dispersion result measurement

(1) In the experimental method, the hydrophilic group of the surface modifier was synthesized by changing the molar ratio of the initiator and glycidol, and 50 wt% of cellulose was added and dispersed, and then it was precipitated in a vacuum state at 80 ° C. under severe conditions. Dispersion stability was measured.

(In FIG. 8, ① X, ② only Span80, ③ Span80: glycidol = 1:1, ④ Span80: glycidol = 1:3, ⑤ Span80: glycidol = 1:5)

(2) The experimental results were as shown in FIG. 8 . From the left, no dispersant is added (X), interaction promoter without a hydroxyl group, interaction promoter with one hydroxyl group, and 3 or 5 interaction promoters added. (For each type of polyol, the appropriate hydroxyl group and amount of the interaction promoter are different.)

(3) From the above results, it was confirmed that the most suitable dispersion stability was when 50 wt% of the surface modifier cellulose synthesized with PTMG1000 standard Span80: glycidol = 1:3 was added (④).

Experimental Example 6. Polyol dispersion results according to the amount of surface modifier

(1) The experimental method is the same as in Experimental Example 5, but the surface modifier is the same Span80: put the surface modifier synthesized with glycidol = 1: 3 by weight relative to each cellulose, sufficiently disperse until water is removed, and then Dispersion stability was measured at the rate at which precipitation occurs under harsh conditions of vacuum and 80 °C.

(2) The experimental results were as shown in FIG. 9 . In FIG. 9, from the left compared to cellulose, ① 0 wt%, ② 25 wt%, ③ 50 wt%, ④ 75 wt%, ⑤ 100 wt%, and ⑥ 150 wt%.

(3) From the above results, it was confirmed that the most suitable dispersing power was when 50 wt% of the surface modifier cellulose synthesized with PTMG1000 standard Span80: glycidol = 1:3 (③) had the highest dispersion stability.

Experimental Example 7. DSC measurement of thermoplastic polyurethane according to the amount of surface-modified nanocellulose

(1) The experimental method was 1 wt% of cellulose with a surface modifier added to the weight of PTMG. After preparing 2 wt%, 3wt%, 4wt% and control with thermoplastic polyurethane, put 2 ~ 4 mg of film in DSC and raise the temperature to -70 ℃ ~ 240 ℃ at 10 ℃ / min. Repeatedly, the second data was extracted.

(2) The experimental results were as shown in FIG. 10 .

(3) From the above results, it was confirmed that the glass transition temperature corresponding to the amorphous physical property of thermoplastic polyurethane decreased as the cellulose content increased. As cellulose was added, it was judged to decrease because it affected the entanglement of amorphous, and the reason why melting temperature increased as cellulose was added was because of the hydroxyl of cellulose and the urethane group present in the polyurethane hard segment. This is because the carbonyl group forms a stable hydrogen bond and acts as a composite material.

Experimental Example 8. Measurement of TGA and DTA of thermoplastic polyurethane according to the amount of surface-modified nanocellulose

(1) The experimental method was 1 wt% of cellulose with a surface modifier added to the weight of PTMG. After preparing 2 wt%, 3 wt%, 4 wt% and control with thermoplastic polyurethane, put 7 ~ 8 mg on a pan, increase the temperature to 30 ℃ ~ 800 ℃ at 30 ℃ / min, and hold for 10 minutes Thus, the weight decrease data was obtained.

(2) The experimental results were as shown in FIGS. 11A and 11B.

(3) From the above results, it was confirmed that the two decomposition temperatures increased as the cellulose content of the thermoplastic polyurethane film increased. It was confirmed that the decomposition temperature increased as the cellulose content increased because the hydroxyl group of cellulose and the carbonyl group of the urethane group present in the polyurethane hard segment formed a stable hydrogen bond and acted as a composite material.

Experimental Example 9. UTM of thermoplastic polyurethane according to the amount of surface-modified nanocellulose

(1) For the test method, each film was manufactured in accordance with the standards for specimen production of ASTM standard D638, and this was conducted through a tensile strength test of a universal testing machine.

(2) The experimental results were as shown in FIG. 12 .

(3) As a result of measuring the tensile strength of PU prepared by adding NC as an interaction promoter to polyol, it was confirmed that the tensile strength increased about twice as much when 4% NC was added.

(4) From the above results, there was no significant change in tensile strain, but it was confirmed that the tensile stress increased by about 2 times. Since it forms a composite material and serves as a composite material, it was confirmed that the tensile strength was affected as the cellulose content increased.

Claims (18)

In the nanocellulose surface modifier,
The nanocellulose surface modifier is a nonionic surfactant in which a hydrophilic group is ring-opened with glycidol, a nanocellulose surface modifier.
According to claim 1,
The nonionic surfactant is a nonionic surfactant prepared by a ring-opening reaction between at least one of a carboxylic acid compound having 4 to 25 carbon atoms, an alcohol compound having 4 to 25 carbon atoms, and an amine compound having 4 to 25 carbon atoms and glycidol, Nanocellulose surface modifier.
According to claim 2,
The carboxylic acid compound having 4 to 25 carbon atoms is butyric acid, valeric acid, caproic acid, enatic acid, caprylic acid, ferragonic acid, capric acid, undecylic acid, lauric acid, tridecylic acid, myristic acid, pentadecyl Lyric acid, palmitic acid, margaric acid, stearic acid, nonadesilic acid, arachitic acid, heneicosilic acid, behenic acid, trichosilic acid, lignoceric acid, alpha-linolenic acid, stearidonic acid, icosapentaeno Iksan, docosahexaenoic acid, linolic acid, gamma-linoleic acid, dihomo-gamma-linoleic acid, arachinonic acid, docosatetraenoic acid, palmitoleic acid, vasenic acid, paulinic acid, oleic acid, At least one selected from elaidic acid, gondoic acid, erusic acid, nervonic acid, and mead acid,
The alcohol compound having 4 to 25 carbon atoms is butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, and palmityl alcohol. At least one selected from octadecanol, nonadecanol, eicosanol, heneicosanol, docosanol, tricosanol, tetracosanol, and pentacosanol,
The amine compound having 4 to 25 carbon atoms is butanamine, pentanamine, hexanamine, heptanamine, octanamine, nonanamine, decanamine, undecaneamine, dodecanamine, tritecanamine, tetradecaneamine, pentadecanamine, At least one selected from hexadecaneamine, heptadecanamine, octadecanamine, nonadecanamine, icosanoic acid amine, hennicosanamine, docosanamine, trichosanamine, tetrachosanoic acid amine, and pentacosanoic acid amine,
Nanocellulose surface modifier.
According to claim 1,
The nanocellulose surface modifier is a hyperbranched polyglycidol (Hyerbranched polyglycidol, HBPG) form, nanocellulose surface modifier.
According to claim 1,
The nanocellulose surface modifier is prepared by reacting at least one of a carboxylic acid compound having 4 to 25 carbon atoms, an alcohol compound having 4 to 25 carbon atoms, and an amine compound having 4 to 25 carbon atoms and glycidol in a molar ratio of 1: 1 to 30 Phosphorus, nanocellulose surface modifier.
According to claim 5,
The nanocellulose surface modifier is a nanocellulose surface modifier prepared by reacting a carboxylic acid compound having 4 to 25 carbon atoms with glycidol in a molar ratio of 1: 1 to 8.
According to claim 1,
The nanocellulose surface modifier is a nanocellulose surface modifier having 1 to 10 hydroxyl groups.
In the method for preparing the nanocellulose surface modifier of any one of claims 1 to 7, the method
Injecting at least one of a carboxylic acid compound having 4 to 25 carbon atoms, an alcohol compound having 4 to 25 carbon atoms, and an amine compound having 4 to 25 carbon atoms and a catalyst;
Nitrogen purging at 80° C. to 120° C. for 30 minutes to 5 hours; and
A method for producing a nanocellulose surface modifier, comprising: reacting for 4 to 48 hours after adding glycidol.
In the method for producing surface-modified nanocellulose, the method
Mixing the nanocellulose aqueous solution and the nanocellulose surface modifier of any one of claims 1 to 7;
Centrifuging the mixed solution; and
Method for producing nanocellulose with a modified surface comprising; removing a large amount of water after centrifugation.
According to claim 9,
The nanocellulose and the nanocellulose surface modifier contained in the nanocellulose aqueous solution are mixed in a weight ratio of 1 to 0.2 to 3, the method of producing a surface-modified nanocellulose.
A surface-modified nanocellulose prepared according to the method of claim 9.
According to claim 11,
The surface-modified nanocellulose is in the form of a slurry, surface-modified nanocellulose.
According to claim 11,
The surface-modified nanocellulose is one in which the surface modifier and the nanocellulose are bonded by a hydrogen bond, surface-modified nanocellulose.
In the method for producing a polyol polymer mattress in which nanocellulose is dispersed,
Dispersing, injecting or adding nanocellulose whose surface is modified with the nanocellulose surface modifier of any one of claims 1 to 7 in a polyol; Method for producing a polyol polymer matrix in which nanocellulose is dispersed.
15. The method of claim 14,
The method further comprises removing water from the mixed solution; a method for producing a polyol polymer mattress in which nanocellulose is dispersed.
15. The method of claim 14,
Method for producing a polyol polymer mattress in which nanocellulose is dispersed, wherein the surface-modified nanocellulose is included in 0.1% to 10% by weight of polyol based on the total weight of the polyol polymer mattress.
A polyol polymer mattress in which nanocellulose prepared according to claim 14 is dispersed.
18. The method of claim 17,
The polyol polymer mattress has improved tensile strength and heat resistance, a polyol polymer mattress.

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